Composite negative electrode, preparation method of negative electrode and lithium-sulfur secondary battery with negative electrode

Abstract

The invention discloses a composite negative electrode, a preparation method of the negative electrode and a lithium-sulfur secondary battery with the negative electrode. The composite negative electrode comprises copper foil and a solid lithium ion conductive diaphragm tape, wherein one end of the copper foil is provided with a tab for conducting current, at least one side of the copper foil is closely provided with metal lithium foil or alloy lithium foil which is used as a battery negative electrode, and the solid lithium ion conductive diaphragm tape covers the battery negative electrode, so that the accumulation of lithium ions on a negative electrode lithium alloy surface and the short circuit, caused by lithium dendrites, between a positive electrode and the negative electrode of the battery can be prevented. In the manner, on the premise of maintaining high energy density, the safety performance of the lithium-sulfur battery can be improved. In addition, multi-element compound electrolyte is used for substituting for organic electrolyte, so that the dissolving and diffusion of sulfur in the electrolyte can be effectively prevented, and the cycling life of the battery can be greatly prolonged.

Description

technical field [0001] The invention relates to the technical field of secondary batteries, in particular to a composite negative electrode for lithium-sulfur secondary batteries, a preparation method and the lithium-sulfur secondary battery. Background technique [0002] Since John Goodenough, a professor at the University of Texas in 1979, invented lithium compounds (such as lithium cobaltate, lithium nickelate and lithium manganate, etc.) as positive electrode materials for secondary batteries, global battery companies have started production of lithium metal secondary batteries. and sales history. [0003] Lithium metal secondary batteries at that time used lithium foil as the negative electrode, a lithium compound as the positive electrode, and an organic liquid solution as the electrolyte. However, when the battery is being charged, lithium metal accumulation and lithium dendritic growth occur on the surface of the lithium foil negative electrode, resulting in a short...

AI Technical Summary

Problems solved by technology

In essence, this technology reduces the growth of lithium dendrites by reducing the porosity of the separator, but it greatly increases the internal resistance of the battery and sacrifices the high-power discharge performance of the secondary battery.

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